THE CAST OF THAT '70S SHOW

Talk about a blast from the past: Seven years after the sitcom ended its eight-year run in 2006, Topher Grace, Ashton Kutcher, girlfriend Mila Kunis, Danny Masterson, Wilmer Valderrama and Laura Prepon partied like it was 1976 all over again at an Oct. 8, 2013, get-together-turned-karaoke session in Los Angeles. "Every once in awhile friends gather for a 6 part harmony of a BigStar song," Masterson captioned the snapshot on Instagram in a nod to That '70s Show's theme song.